Power amplifier circuit and method of design

ABSTRACT

Structure and design methods of electrical power amplifiers suitable for broadband application such as television frequency or white spaces. An example broadband power amplifier passes a transmit carrier with modulations from BPSK to 256 QAM, on channel bandwidths from 6 to 32 MHz, over the entire UHF television band from 470 to 800 MHz using a low voltage, low power, narrowband power amplifier transistor. Based on a push-pull technique to lower the impedance level thus improving the match and doubling the power, the wide-band power amplification is performed with a balanced polynomial filter transform structure wherein the circuit impedance increases sequentially within the filter stage. The polynomial filtering makes high selectivity of out-of-band signals thereby cleaning up harmonic signals which prevent the need for additional high selective radio frequency filters. The invented power amplifier enables efficient broadband power amplifiers having a form factor within 300 square millimeters of space.

FIELD OF THE INVENTION

The present invention relates to electrical circuitry design andstructure. More particularly, the present invention relates to thestructure and design methods of electrical power amplifiers.

BACKGROUND OF THE INVENTION

The subject matter discussed in the background section should not beassumed to be prior art merely as a result of its mention in thebackground section. Similarly, a problem mentioned in the backgroundsection or associated with the subject matter of the background sectionshould not be assumed to have been previously recognized in the priorart. The subject matter in the background section merely representsdifferent approaches, which in and of themselves may also be inventions.

The advantages of employing broadband amplifiers that selectively applyelectrical power to increase the output strength of input signalsreceived within pre-specified frequency bands are desirable in manyareas of electrical and electronic systems design, fabrication and use.In communications system technology, offered as one example and notintended as a limitation of the scope of the method of the presentinvention, the use of power amplifiers in transceiver architectures thatprovide signal amplification in frequency bands especially suited forthe intended purpose of a system embodying a particular transceiverarchitecture offers many advantages. Firstly, the performance advantageof increasing signal strength primarily or essentially only in thosefrequency bands of interest to an intended user can be improved byknowledgeable power amplifier design. Secondly, conserving electricalpower by expending energy primarily in providing the most desired outputsignal frequency bands reduces energy wastage, reduces cost ofoperations, and extends the time of effectiveness of an electricalbattery or a capacitive source of electrical energy. Additionalparameters of interest in a power amplifier design include (a.) reducingcost of components of the power amplifier circuit; (b.) reducing therequired footprint and operating volume of the desired power amplifiercircuit within its comprising system; (c.) imposing modest or littlechallenge in manufacturability of the desired power amplifier circuitwithin its comprising system; and (d.) imposing lower insertion lossperformance by the desired power amplifier circuit upon its comprisingsystem. It is understood that a reduction in insertion loss translatesinto an increased possible maximum output power, and thereby enables animprovement in overall power efficiency, of the comprising amplifier ortransceiver.

Broadband power amplifiers in wireless communications systems preferablypresent transistor power matching over large frequency ranges.Furthermore, it is generally desirable in electronic systems adapted totransmit radio waves that a power amplifier present an impedance matchhaving a radio characteristic impedance, e.g., 50 ohm or 75 ohm, to anycoupled transistor impedance, wherein the target impedance is usuallylow ohmic due that may be caused by a high capacitive impedanceresulting from by a relatively large transistor having a high draincurrent.

Prior art power amplifiers often use transformer topologies to generatea 180° phase shift and provide impedance matching. The prior art designapproach to high frequency and broadband coverage includes applyingtopologies that include Ruthroff circuits and/or Guanella structures.These prior art circuits are usually used for broadband transform anddeliver a four to ten impedance value obtained with a penalty up to 2 dBof insertion losses.

Some prior art alternatives provide cascaded transformers intended tooptimize the phase shift in a first stage and then a transformerimpedance characteristic in a second stage. As the mains terminalcapacitors cause a low ohmic impedance of the power amplifiertransistors, some designs use cascade structures to reduce the input oroutput capacitor in reliance upon the well-known Miller effect. Thetotal resulting impedance of prior art power amplifiers may then beimproved by introduction and use of a feedback network which reduces thepower gain of the amplifier.

The prior art fails to offer optimized power amplifier designs thatapply band pass filtering techniques and circuits that at leastpartially compensate for any performance effect imposed by the inclusionof simplified transformer elements within a power amplifier circuit.

SUMMARY OF THE INVENTION

Towards these objects and other objects that will be made obvious inlight of the present disclosure presents and fully discloses an inventedpower amplifier and method of design therefore that avoid inclusion ofrelatively expensive transformer components. In accordance with themethod of the present invention (hereinafter, “the invented method”), apower amplifier includes a pair of signal amplifying transistors andsignal-filtering stages are separately positioned preferably onetransistor of the pair of transistors. Each stage preferably providesboth (a.) an inductance oriented in series with an inductance of one ormore additionally electrically coupled stages, and (b.) a capacitanceoriented in parallel with a capacitance of these one or moreadditionally electrically coupled stages. In combination, the pluralityof signal filtering inductance-capacitance circuit stages filter outcertain frequency contributions of a received input signal and cause anoutput amplified signal to be particularly responsive withinpre-selected frequency signal bands.

In one optional aspect of the invented method, the signal filteringcircuit stages coupled with an input feature of either transistor arecoupled with and receive an input signal through a single windingtransformer circuit, whereby the input signals are filtered prior tointroduction to the signal input feature of the coupled transistor. Inanother optional aspect of the invented method, the signal filteringcircuit stages that are coupled with a signal power output feature ofone of the power amplifier transistors deliver a resultant amplifiedoutput signal from the coupled transistor and to a single windingtransformer circuit.

In a still other optional aspect of the invented method, the signalfiltering circuit stages coupled with an input feature of eithertransistor are coupled with and receive an input signal through a baluntransformer circuit, whereby the input signals are filtered prior tointroduction to the signal input feature of the coupled transistor. In ayet other optional aspect of the invented method, the signal filteringcircuit stages that are coupled with a signal power output feature ofone of the power amplifier transistors deliver a resultant amplifiedoutput signal from the coupled transistor and to another baluntransformer circuit.

Certain alternate preferred embodiments of the invented methodaccommodate low cost components, such as transistors that evidencerelatively high capacitance.

A first preferred embodiment of the invented method includes on ore moreof the steps of (1.) determining one or more preferred bands of signalfrequencies of which it is desired to increase in amplitude; (2.) theselection of an input and an output transformer that each approximatelyperform as comprising no more than a single winding, such as a baluntransformer; (3.) selecting two power transistors of known electricalcharacteristics and tolerances; (4.) determining one or moreinductor-capacitor stages that in series provide a desirable effect offiltering an input signal to reduce or eliminate frequencies outside ofthe preferred bands of signal frequencies; (5.) determining one or moreinductor-capacitor stages that in series provide a desirable effect offiltering an output signal or one of the two transistors to reduce oreliminate frequencies outside of the preferred bands of signalfrequencies; and (6.) selecting components, such as discrete components,to embody the design choices and preferences of the previous designsteps. The selected components are then electrically coupled to a sourceof electrical energy form a power amplifier.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

These, and further features of the invention, may be better understoodwith reference to the accompanying specification and drawings depictingthe preferred embodiment, in which:

FIG. 1 is a schematic of a prior art wireless communications transceiverthat includes a prior art power amplifier;

FIG. 2A is a schematic of a first preferred embodiment of the presentinvention wherein each of two power transistors are coupled with aninput band pass circuit and an output band pass circuit;

FIG. 2B is an alternate schematic of a second preferred embodiment ofthe present invention wherein each of the pair of input band passcircuits of FIG. 2A are coupled with an input balun circuit and each ofthe pair of output band pass circuits of FIG. 2A are coupled with anoutput balun circuit;

FIG. 3A is an stepped filter that presents an abstraction of thestructure of any one of the two input band pass circuits and the twooutput band pass circuits of FIG. 2A and FIG. 2B, wherein FIG. 3A issuitable for modeling a multi-stage low-pass or band pass type impedancetransform circuit;

FIG. 3B is a representation of a Voltage Standing-Wave Ratio(hereinafter, “VSWR”) signal frequency filtering performance inCartesian coordinates of a circuit structured in accordance with thestepped filter design of FIG. 3A, i.e., FIG. 3B is a visual graphrepresentation of impedance matching of the muti-stage impedancetransform circuit of FIG. 3A;

FIG. 3C is a representation of a wide-band impedance transformperformance in polar coordinates of a circuit structured in accordancewith the stepped filter, or muti-stage impedance transform circuit, ofFIG. 3A;

FIG. 4 is an additional schematic that presents an abstraction of apower amplifier designed and structured in accordance with the inventedmethod;

FIG. 5A is circuit schematic that presents an abstraction of a firstinvented power amplifier designed and structured in accordance with theinvented method and presented with specific and enumerated capacitiveand inductance values and effects;

FIG. 5B is a graph in Cartesian coordinates of a simulated amplifiergain calculated in view of the enumerated capacitive and inductancevalues and effects of the invented power amplifier of FIG. 5A;

FIG. 5C is a graph in Cartesian coordinates of a simulated broadbandamplifier input/output return loss, image of the impedance calculated inview of the enumerated capacitive and inductance values and effects ofthe invented power amplifier of FIG. 5A;

FIG. 5D is a graph in polar coordinates of a simulated broadbandamplifier input/output impedance calculated in view of the enumeratedcapacitive and inductance values and effects of the invented poweramplifier of FIG. 5A;

FIG. 6 presents an application of a prior art technique to deriveinductance values and capacitance values for elements of two band passfilter stages of FIG. 3A of the invented band pass filters of FIGS. 2A,2B, 4, and 5A;

FIG. 7 presents an application of a prior art technique to deriveinductance values and capacitance values for elements of three band passfilter stages FIG. 3A of the invented band pass filters of FIGS. 2A, 2B,4, and 5A;

FIG. 8 presents a desired frequency response of a three band pass filterstages of FIG. 7;

FIG. 9 is yet an additional schematic that presents an abstraction of afourth alternate preferred embodiment of the invented power amplifierdesigned and structured in accordance with the invented method;

FIG. 10 is yet an additional schematic that presents an abstraction of afifth alternate preferred embodiment of the invented power amplifierdesigned and structured in accordance with the invented method; and

FIG. 11 is yet an additional schematic that presents an abstraction of asixth alternate preferred embodiment of the invented power amplifierdesigned and structured in accordance with the invented method.

DETAILED DESCRIPTION

Referring now generally to the Figures and particularly to FIG. 1, FIG.1 is a schematic of a prior art wireless communications transceiver 100that includes a prior art power amplifier 102. It is understood that theschematic of FIG. 1 presents a prior art transceiver architecture withinwhich certain alternate embodiments of the present invention may beintegrated as, or within, a power amplifier.

Examples of electronic device products that may serve as or be comprisedwithin the prior art power amplifier 102 include (a.) broadbandtransformer HHM1589 OCTOPART™ broadband transformer marketed by TDK ofTokyo, Japan and having a ratio 1 to 4; (b.) an RFXF6553™ broadbandtransformer marketed by MiniRF, Inc. of Fremont, Calif. and having aratio 1 to 4, and (c.) DXP18BN5014H broadband transformer as marketed byMurata of Kyoto, Japan.

It is understood that the design of high frequency and broadbandcoverage communications equipment that various embodiments of theseequipment types may employ or include either a Ruthroff transformer or aGuanella transformer structure, wherein prior art broadband transformerperformance may present a four to ten impedance value with penalty up to2 dB of insertion losses. Prior art power amplifier usually use thosetransformer topologies to generating the desired 180° phase shift andimpedance matching. Some prior art alternatives also make use ofcascaded transformers to optimize the desired phase shift in a firststage and then an impedance transform in a second stage. Since the mainsterminal capacitors of many such prior art circuits cause a low ohmicimpedance of the power amplifier transistors, some prior art designs usecascade structures to reduce an input or output capacitor in relianceupon the Miller effect, wherein the impedances of the prior art circuitsare fine tuned with feedback network which reduces the power gain of theamplifier.

Referring now generally to the Figures and particularly to FIG. 2A, FIG.2A is a schematic of a first preferred embodiment 200 of the presentinvention wherein each of two power transistors T1 and T2 are each arecoupled with an input band pass circuit 201A & 201B and an output bandpass circuit 201C & 201D and comprising an input transformer 202Apreferably presenting a 1:1 ratio and an output transformer 202B that isalso preferably presenting a 1:1 ratio. The input transformer 202A iscoupled to an input electrical power source 204. The output transformer202B is coupled to an energy output circuit 206.

It is understood that the upper input band pass circuit 201A, the lowerinput band pass circuit 201B, the upper output band pass circuit 201C,and the lower output band pass circuit 201D each compriseinductor-capacitor stages (hereinafter, “LC stage(s)”) as furtherdisclosed and enabled herein.

The first transistor T1 and the second transistor T2 may be or comprisea Heterojunction Bipolar Transistor, a Laterally-Diffused Metal-OxideSemiconductor, a Bipolar Junction Transistor (hereinafter, “BJT”), aField Effect Transistor (hereinafter, “FET”) such as, but not limited toa Heterojunction FET, a Metal Oxide Semiconductor FET, (hereinafter,“MOSFET”), and/or an other suitable transistor type known in the art.

Where the first transistor T1 and the second transistor T2 are eachFET's, the drain of the first transistor T1 and the second transistorT2are separately electrically coupled with an electrical power source(not shown), such as a battery or other suitable electrical power sourceknown in the art. In addition, when the first transistor T1 and thesecond transistor T2 are each FET's, the upper input band pass circuit201A is electrically coupled to a first gate terminal of the firsttransistor T1 and the upper output band circuit 201C is electricallycoupled to the source terminal of the first transistor T1; the lowerinput band pass circuit 201B is electrically coupled to a second gateterminal of the second transistor T2 and the lower output band circuit201D is electrically coupled to the source terminal of the secondtransistor T2.

Where the first transistor T1 and the second transistor T2 are eachBipolar transistors, the collector of the first transistor Ti and thecollector of the second transistor T2 are separately electricallycoupled with the electrical power source (not shown), such as a batteryor other suitable electrical power source known in the art. In addition,when the first transistor T1 and the second transistor T2 are eachindividual Bipolar transistors, the upper input band pass circuit 201Ais electrically coupled to a first base terminal of the first transistorT1 and the upper output band circuit 201C is electrically coupled to theemitter terminal of the first transistor T1; the lower input band passcircuit 201B is electrically coupled to a second base terminal of thesecond transistor T2 and the lower output band circuit 201D iselectrically coupled to the emitter terminal of the second transistorT2.

It is understood that the first preferred embodiment 200 may be designedand embodied to operate as a Class A power amplifier, a Class B poweramplifier, a Class AB power amplifier, or a Class C power amplifier.Accordingly, the first transistor T1 and the second transistor T2 arepreferably selected from suitable transistor designs and products knownin the art that support and enable the operation of the first preferredembodiment 200 to meet the generally accepted performance standard ofthe intended power amplifier Class.

Referring now generally to the Figures and particularly to FIG. 2B, FIG.2B is an alternate schematic of a second preferred embodiment of thepresent invention 208 (hereinafter, “the second invented power amplifier208”) , wherein each of the pair of input band pass circuits 201A & 201Bare coupled with an input 1:1 balun circuit 210A and each of the pair ofoutput band pass circuits 201C & 201D are coupled with an output 1:1balun circuit. 210B.

The second invented power amplifier 208 has push-pull architecture with1:1 ballun at input and output. The second invented power amplifier 208can achieve wide bandwidth required in some applications, such as TVwhite spaces 470-800 MHz, and evidence low insertion losses thatimprovements in power gain and output power and efficiency.

Once balanced, the impedance presented to the two active transistors T1& T2 is half of the input or output impedance. If the termination of thesecond invented power amplifier 208 is at 50 Ohm, then 25 Ohm will bepresented to each of the active transistors T1 & T2. In order to matchthis impedance to the input/output impedance of the active transistorsT1 & T2 that can be as low as in the range of from one Ohm to five Ohmsor alternatively higher in impedance. A stepped polynomial filter isthen designed, integrated into, and used to smoothly adapt the impedanceof the second invented power amplifier 208 such as the impedancematching second invented power amplifier 208 is guaranteed over a widefrequency range.

It is understood that second invented power amplifier 208 may bedesigned and embodied to operate as a Class A power amplifier, a Class Bpower amplifier, a Class AB power amplifier, or a Class C poweramplifier. Accordingly, the first transistor T1 and the secondtransistor T2 are preferably selected from suitable transistor designsand products known in the art that support and enable the operation ofthe second invented power amplifier 208 to meet the generally acceptedperformance standard of the intended power amplifier Class.

Referring now generally to the Figures and particularly to FIG. 3A, FIG.3A presents the exemplary structure of a stepped band pass filter 300that may be embodied by any one of the two input band pass circuits 201A& 201B and/or the two output band pass 201C & 201D circuits. It isunderstood that one or more of the two input band pass circuits 201A &201B and/or the two output band pass 201C & 201D circuits may bestructured and perform as a low band pass filter.

It is understood that the input electrical power source 204 comprises anenergy source E and a source resistance Rs of 25 ohms and the energyoutput circuit 206 comprises an input resistance Rn+1.

The stepped filter 300 as embodied by any of the band pass circuits201A, 201B, 201C & 201D includes a plurality of LC stages 300.A-300.N/2,wherein N is an arbitrarily large number that is greater than the numberone. A first stage 300.A includes a first inductor L1 that is placed inseries with the other LC stages 300.A-300.N and a first capacitor C2that is placed in parallel with the other LC stages 300.B-300.N. Asecond stage 300.B includes (1.) a second inductor L3 that is placed inseries with the other LC stages 300.A & 300.N, and (2.) a secondcapacitor C4 that is placed in parallel with the other LC stages300.A-300.N. A Nth stage 300.N includes (1.) an Nth inductor Ln−1 thatis placed in series with the other LC stages 300.A & 300.B, and (2.) Nthcapacitor Cn that is placed in parallel with the other LC stages300.A-300.N.

Referring now generally to the Figures and particularly to FIG. 3B, FIG.3B is a representation of a VSWR frequency filtering performance inCartesian coordinates of a band pass circuit 201A, 201B, 201C & 201Dstructured in accordance with the idealized schematic of the steppedfilter 300.

Referring now generally to the Figures and particularly to FIG. 3C, FIG.3C is a representation of a signal frequency filtering performance inpolar coordinates of a band pass circuit 201A, 201B, 201C & 201Dstructured in accordance with the stepped filter 300.

Referring now generally to the Figures and particularly to FIG. 4, FIG.4 is an additional schematic that presents an abstraction of anexemplary third invented power amplifier 400 designed and structured inaccordance with the invented method. The third invented power amplifier400 includes (1.) an alternate upper input band pass filter 401Acomprising three LC stages coupled with an input of the first transistorT1; (2.) an alternate lower input band pass filter 401B comprising threeLC stages coupled with an input of the second transistor T2; (3.) analternate upper output band pass filter 401C comprising two LC stagescoupled with the output of the first transistor T1; and (4.) analternate lower output band pass filter 401D comprising two LC stagescoupled with the output of the second transistor T2.

It is understood that the impedance characteristics of the components ofthe third invented power amplifier 400 may be chosen and selected inaccordance with a generation of a polynomial expression comprisingChebychev coefficients, whereby a preferred distribution of resonatorfrequency of each LC filter stage of each the alternate band pass filter401A, 401B, 401C & 401D giving a more desirable or lowest insertion lossand improved or best frequency bandwidth for the third invented poweramplifier 400.

It is further understood that the third invented power amplifier 400 maybe designed and embodied to operate as a Class A power amplifier, aClass B power amplifier, a Class AB power amplifier, or a Class C poweramplifier. Accordingly, the first transistor T1 and the secondtransistor T2 are preferably selected from suitable transistor designsand products known in the art that support and enable the operation ofthe second invented power amplifier 208 to meet the generally acceptedperformance standard of the intended power amplifier Class.

The third invented power amplifier 400 has been implemented as a devicehaving a footprint of less than 250 square millimeters and delivering2.5 Watts in output signal energy in consuming five Watts of electricalpower from a five Volt supply. In contrast, a typical prior art poweramplifier reference design as marketed by Triquint of Hillsboro, Oreg.based on the inclusion of a more expensive transformer element presentsa 380 square millimeter footprint and consumes 10 W with 12 Volt, 24Volt or 28 Volt power source and delivers only two Watts in max outputsignal power.

The third invented power amplifier 400 can be embodied with a 1:1 baluntransformer having insertion losses in the range of from 0.5 decibel to0.7 dB whereas a prior art power amplifier that incorporates a prior artbroadband transformer would more typically present a 1.5 decibel to 2.0decibel insertion loss.

Prior art design techniques typically require trade off decisions ininsertion loss magnitude versus balancing or phase shift of the priorart transformer, so designers have generally preferred in the prior artto prefer to cascade two transformers, wherein a first transformerprovides the desired phase shifting and a second transformer providesfor an impedance transform. Prior art power amplifier transforms thusoften evidence the power losses in the range form 2.0 decibels to 2.5decibels which directly impact the maximum output power to delivered bythe prior art device, and therefore efficiency of the prior art device.

Referring now generally to the Figures and particularly to FIG. 5A, FIG.5A is circuit schematic of an exemplary fourth invented power amplifier500 designed and structured in accordance with the invented method andpresented with specific and enumerated capacitive and inductance valuesand effects.

The fourth invented power amplifier 500 includes four still alternateband pass filters 501A, 501B, 501C & 501D, the input 1:1 balun circuit210A, and the output 1:1 balun circuit. The still alternate upper inputband pass filter 501A comprises a first capacitor C1 positioned inseries with the first transistor T1, a second capacitor C2 positioned inparallel with the first transistor T1, a first inductor L1 positioned inseries with the first transistor T1, a third capacitor C3 positioned inparallel with the first transistor T1, a second inductor L2 positionedin series with the first transistor T1, and a fourth capacitor C4positioned in parallel with the first transistor T1. It is understoodthat the first inductor Ll and the third capacitor C3 form a band passfilter stage of the still alternate upper input band pass filter 501Aand further that the a second inductor L2 and the fourth capacitor C4also form a band pass filter stage of the still alternate upper inputband pass filter 501A.

Exemplary values of impedance characteristics of the elements of thestill alternate upper input band pass filter 501A include 100 pF ofcapacitance for the first capacitor C1; 15 pF of capacitance for thesecond capacitor C2; 22 pF of capacitance for the third capacitor C3; 33pF of capacitance for the fourth capacitor C4; 3.9 nH of inductance forthe first inductor L1; and 1.3 nH of inductance for the second inductorL2.

The still alternate upper output band pass filter 501C comprises a fifthcapacitor C5 positioned in series with the output gate of the firsttransistor T1, a third inductor L3 positioned in series with the outputgate of the first transistor T1, a sixth capacitor C6 positioned inparallel with the output gate of the first transistor T1, and a seventhcapacitor C7 positioned in series with the output gate of the firsttransistor T1. It is understood that the third inductor L3 and the sixthcapacitor C6 form a band pass filter stage of the still alternate upperoutput band pass filter 501C. Exemplary values of impedancecharacteristics of the elements of the still alternate upper output bandpass filter 501C include 47 pF of capacitance for the fifth capacitorC5; 12 pF of capacitance for the sixth capacitor C6; 100 pF ofcapacitance for the seventh capacitor C7; and 4.3 nH of inductance forthe third inductor L3.

The still alternate lower input band pass filter 501B comprises aneighth capacitor C8 positioned in series with the second transistor T2,a ninth capacitor C9 positioned in parallel with the second transistorT2, a fourth inductor L4 positioned in series with the second transistorT2, a tenth capacitor C10 positioned in parallel with the secondtransistor T2, a fifth inductor L5 positioned in series with the secondtransistor T2, and an eleventh capacitor C11 positioned in parallel withthe second transistor T2. It is understood that the fourth inductor L4and the tenth capacitor C10 form a band pass filter stage of the stillalternate lower input band pass filter 501B and further that the fifthinductor L5 and the eleventh capacitor C11 also form a band pass filterstage of the still alternate lower input band pass filter 501B.

Exemplary values of impedance characteristics of the elements of thestill alternate upper input band pass filter 501B include 100 pF ofcapacitance for the eighth capacitor C8; 15 pF of capacitance for theninth capacitor C9; 22 pF of capacitance for the tenth capacitor C10; 33pF of capacitance for the eleventh capacitor C11; 3.9 nH of inductancefor the fourth inductor L4; and 1.3 nH of inductance for the fifthinductor L5.

The still alternate lower output band pass filter 501D comprises atwelfth capacitor C12 positioned in series with the output gate of thesecond transistor T2, a sixth inductor L6 positioned in series with theoutput gate of the second transistor T2, a thirteenth capacitor C13positioned in parallel with the output gate of the second transistor T2,and a fourteenth capacitor C14 positioned in series with the output gateof the second transistor T2. It is understood that the sixth inductor L6and the fourteenth capacitor C14 form a band pass filter stage of thestill alternate lower output band pass filter 501D. Exemplary values ofimpedance characteristics of the elements of the still alternate loweroutput band pass filter 501D include 47 pF of capacitance for thetwelfth capacitor C12; 12 pF of capacitance for the thirteenth capacitorC13; 100 pF of capacitance for the fourteenth capacitor C7; and 4.3 nHof inductance for the sixth inductor L6

The fourth invented power amplifier 500 further comprises a pull upinductor L7 coupled with the output gate of the first transistor T1 anda local DC power source Vcc and a pull down inductor L8 coupled with theoutput gate of the second transistor T2 and the local DC power sourceVcc.

Referring now generally to the Figures and particularly to FIG. 5B, FIG.5B is a graph in Cartesian coordinates of a simulated amplifier gaincalculated in view of the enumerated capacitive and inductance valuesand effects of the fourth invented power amplifier 500.

Referring now generally to the Figures and particularly to FIG. 5C, FIG.5C is a graph in Cartesian coordinates of a simulated broadbandamplifier input/output impedance calculated in view of the enumeratedcapacitive and inductance values and effects of the fourth inventedpower amplifier 500.

Referring now generally to the Figures and particularly to FIG. 5D, FIG.5D is a graph in polar coordinates of a simulated broadband amplifierinput/output impedance calculated in view of the enumerated capacitiveand inductance values and effects of the fourth invented power amplifier500.

Referring now generally to the Figures and particularly to FIG. 6, FIG.6 presents an application of a prior art technique to derive inductancevalues and capacitance values for elements of two band pass filterstages 300.01-300.N/2 of the invented filters 201A-201D, 401A-401D &501A-501D.

Referring now generally to the Figures and particularly to FIG. 7, FIG.7 presents an application of a prior art technique to derive inductancevalues and capacitance values for elements of three band pass filterstages 300.01-300.N/2 of the invented filters 201A-201D, 401A-401D &501A-501D.

Referring now generally to the Figures and particularly to FIG. 8, FIG.8 presents a desired frequency response of a three band pass filterstages 300.01-300.N/2 of the invented filters 201A-201D, 401A-401D &501A-501D.

Referring now generally to the Figures and particularly to FIG. 9, FIG.9 is yet an additional schematic that presents an abstraction of afourth alternate preferred embodiment 900 of the invented poweramplifier designed and structured in accordance with the inventedmethod. The fourth alternate preferred embodiment 900 (hereinafter, “thefourth amplifier 900”) of the invented power amplifier comprises asystem that accepts a differential input signal Vin and whereby thedifferential input signal Vin traverses an input isolation transformer902. The signal produced from the input transformer 902 traverses a twoseries of inductors L1 through Ln−1 and a plurality of capacitors C1-Cnpositioned in parallel. A resultant signal proceeds from the Cncapacitor to the pair of operational amplifiers T1 &T2; and therefromthrough an additional two series of inductors L′m−1 through L1 and aplurality of capacitors C′m-C′2 positioned in parallel. An additionalresultant signal proceeds from the pair of inductors L′1 through anoutput isolation transformer 904.

Referring now generally to the Figures and particularly to FIG. 10, FIG.10 is yet an additional schematic that presents an abstraction of afifth alternate preferred embodiment 1000 of the invented poweramplifier designed and structured in accordance with the inventedmethod. The fifth alternate preferred embodiment 1000 (hereinafter, “thefifth amplifier 1000”) of the invented power amplifier comprises asystem that accepts a differential input signal Vin and whereby thedifferential input signal Vin traverses an input isolation transformer902. The signal produced from the input transformer 902 traverses eachof two series of capacitors C1-Cn−1 and a plurality of inductors L2-Ln.Each of the two plurality of inductors L2-Ln are positioned in paralleland separately grounded. A resultant signal proceeds from the Lninductor pair to the pair of operational amplifiers T1 &T2; andtherefrom through an additional two series of capacitors C′m-1-C′1 and aplurality of inductor pairs L′m-L′2 positioned in parallel. Each of thetwo plurality of inductors L′m-L′2 are positioned in parallel andseparately grounded. An additional resultant signal proceeds from thepair of capacitors C′1 through the output isolation transformer 904.

Referring now generally to the Figures and particularly to FIG. 11, FIG.11 is yet an additional schematic that presents an abstraction of asixth alternate preferred embodiment 1100 of the invented poweramplifier designed and structured in accordance with the inventedmethod. The sixth alternate preferred embodiment 1100 (hereinafter, “thesixth amplifier 1100”) of the invented power amplifier comprises asystem that accepts a differential input signal Vin and whereby thedifferential input signal Vin traverses an input isolation transformer902. The signal produced from the input transformer 902 traverses eachof two series of capacitors C1-Cn−1 and a plurality of inductors L2-Ln.Each of the plurality of inductors L2-Ln are positioned in parallel. Aresultant signal proceeds from the Ln inductor to the pair ofoperational amplifiers

T1 &T2; and therefrom through an additional two series of capacitorsC′m-1-C′1 and a plurality of inductors L′m-L′2 positioned in parallel.An additional resultant signal proceeds from the pair of capacitors C′1through the output isolation transformer 904.

The foregoing description of the embodiments of the invention has beenpresented for the purpose of illustration; it is not intended to beexhaustive or to limit the invention to the precise forms disclosed.Persons skilled in the relevant art can appreciate that manymodifications and variations are possible in light of the abovedisclosure.

Additionally, the language used in the specification has beenprincipally selected for readability and instructional purposes, and itmay not have been selected to delineate or circumscribe the inventivesubject matter. It is therefore intended that the scope of the inventionbe limited not by this detailed description, but rather by any claimsthat issue on an application based herein. Accordingly, the disclosureof the embodiments of the invention is intended to be illustrative, butnot limiting, of the scope of the invention, which is set forth in thefollowing claims.

What is claimed is:
 1. An electronic circuit comprising: a single-endedinput port; an input transformer; an output transformer; a single-endedoutput port; and two single-ended amplifier legs connected from theinput transformer to the output transformer, each related to a local DCpower source and a local ground, both single-ended amplifier legsconsisting, in order from input to output, of a first passive band-passfilter, a power amplifier, and a second passive band-pass filter, andwherein the first passive band-pass filter consists of, in order frominput to output, of a series of stages where the stages are composed bya shunt capacitor to the local ground and an inductor in series, whereineach component value of each stages may be expressed as a polynomial. 2.The electronic circuit of claim 1 where the input transformer ratio andthe output transformer ratio are both 1:1.
 3. The electronic circuit ofclaim 1 where the power amplifier consists of a single transistor. 4.The electronic circuit of claim 1, wherein the single transistor is aselected from a transistor group consisting of a Bipolar transistor, aField Effect Transistor, a Metal Oxide Semiconductor Field EffectTransistor, and a hetero-junction transistor.
 5. The electronic circuitof claim 1 where the power amplifier consists of two or more transistorswith their emitters/sources connected in series.
 6. The electroniccircuit of claim 1 where the power amplifier consists of a transistorwith its emitter/source connected to the local ground and itscollector/drain connected to the emitter/source of a transistor with itsbase/gate connected to the local ground.
 7. The electronic circuit ofclaim 1 where the two power amplifiers are driven by a same signal 180degrees out of phase.
 8. The electronic circuit of claim 1 where theinput transformer is a transmission line transformer.
 9. The electroniccircuit of claim 1 where the output transformer is a Ruthrofftransformer.
 10. The electronic circuit of claim 1 where the inputtransformer has a middle access termination.
 11. The electronic circuitof claim 1, wherein each power amplifier is supplied with high impedanceinductor connected to the local DC power source.
 12. The electroniccircuit of claim 1 where the output transformer has middle accesstermination.
 13. An electronic circuit comprising: a single-ended inputport; an input transformer; an output transformer; a single-ended outputport; and two single-ended amplifier legs connected from the inputtransformer to the output transformer, each related to a local DC powersource and a local ground, both single-ended amplifier legs consisting,in order from input to output, of a first passive band-pass filter, apower amplifier, and a second passive band-pass filter, wherein thefirst passive band-pass filter consists of, in order from input tooutput, of a first capacitor in series, a second capacitor to the localground, a first inductor in series, a third capacitor to the localground, a second inductor in series, and a fourth capacitor to the localground.
 14. The electronic circuit of claim 1 where the first passiveband-pass filter is adapted to perform as an impedance transform. 15.The electronic circuit of claim 1, wherein each component value of eachstage of the first passive band-pass filter may be expressed as aChebychev polynomial.
 16. The electronic circuit of claim 1 where thesecond passive band-pass filter is adapted to perform an impedancetransform.
 17. The electronic circuit of claim 1 where the secondpassive band-pass filter consists of, in order from input to output, ofa series of stages wherein each stages comprises an inductors in seriesand a shunt capacitor connected to the local ground, whereby eachcomponent values of each stage may expressed as a polynomial equationsuch as a Chebychev polynomial.
 18. An electronic circuit comprising: asingle-ended input port; an input transformer; an output transformer; asingle-ended output port; and two single-ended amplifier legs connectedfrom the input transformer to the output transformer, each related to alocal DC power source and a local ground, both single-ended amplifierlegs consisting, in order from input to output, of a first passiveband-pass filter, a power amplifier, and a second passive band-passfilter, wherein the second passive band-pass filter consists of, inorder from input to output, a third inductor to the local DC powersource, a fifth capacitor to the local ground, a fourth inductor inseries, a sixth capacitor to the local ground, and a seventh capacitorin series.
 19. The electronic circuit of claiml8, wherein the firstpassive band-pass filter consists of, in order from input to output, ofa first capacitor in series, a second capacitor to the local ground, afirst inductor in series, a third capacitor to the local ground, asecond inductor in series, and a fourth capacitor to the local ground.20. The electronic circuit of claim 19, wherein the second passiveband-pass filter consists of, in order from input to output, a thirdinductor to the local DC power source, a fifth capacitor to the localground, a fourth inductor in series, a sixth capacitor to the localground, and a seventh capacitor in series.